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https://www.arca.fiocruz.br/handle/icict/51173
DISTINCT IMMUNOMODULATORY PROPERTIES OF EXTRACELLULAR VESICLES RELEASED BY DIFFERENT STRAINS OF ACANTHAMOEBA
Author
Affilliation
Universidade Federal de Minas Gerais. Faculdade de Farmácia. Belo Horizonte, Belo Horizonte, MG, Brazil
Universidade Federal de Minas Gerais. Faculdade de Farmácia. Belo Horizonte, Belo Horizonte, MG, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil/Universidade Federal do Espírito Santo. Departamento de Patologia. Vitória, ES, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Universidade Federal de São Paulo. Departamento de Ciências Farmacêuticas. Diadema, São Paulo, SP, Brazil
Universidade Federal do Espírito Santo. Departamento de Patologia. Vitória, ES, Brazil
Universidade Federal do Espírito Santo. Departamento de Patologia. Vitória, ES, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Universidade Federal de Minas Gerais. Faculdade de Farmácia. Belo Horizonte, Belo Horizonte, MG, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil/Universidade Federal do Espírito Santo. Departamento de Patologia. Vitória, ES, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Universidade Federal de São Paulo. Departamento de Ciências Farmacêuticas. Diadema, São Paulo, SP, Brazil
Universidade Federal do Espírito Santo. Departamento de Patologia. Vitória, ES, Brazil
Universidade Federal do Espírito Santo. Departamento de Patologia. Vitória, ES, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Abstract
Free living amoeba of the genus Acanthamoeba are opportunist protozoan involved in corneal, systemic, and encephalic infections in humans. Most of the mechanisms underlying intraspecies variations and pathogenicity are still unknown. Recently, the release of extracellular vesicles (EVs) by Acanthamoeba was reported. However, comparative characterization of EVs from distinct strains is not available. The aim of
this study was to evaluate EVs produced by Acanthamoeba from different genotypes, comparing their proteases profile and immunomodulatory properties. EVs from four environmental or clinical strains (genotypes T1, T2, T4, and T11) were obtained by ultracentrifugation, quantitated by nanoparticle tracking analysis and analyzed by scanning and transmission electron microscopy. Proteases profile was determined
by zymography and functional properties of EVs (measure of nitrite and cytokine production) were determined after peritoneal macrophage stimulation. Despite their genotype, all strains released EVs and no differences in size and/or concentration were detected. EVs exhibited a predominant activity of serine proteases
(pH 7.4 and 3.5), with higher intensity in T4 and T1 strains. EVs from the environmental, nonpathogenic T11 strain exhibited a more proinflammatory profile, inducing higher levels of Nitrite, tumor necrosis factor alpha and interleukin‐6 via TLR4/TLR2 than those strains with pathogenic traits (T4, T1, and T2). Preincubation
with EVs treated with protease inhibitors or heating drastically decreased nitrite concentration production in macrophages. Those data suggest that immunomodulatory effects of EVs may reflect their pathogenic potential depending on the Acanthamoeba strains and are dependent on protease integrity.
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